The Melanoma Genetics Consortium, comprising groups with diverse expertise from the USA, Europe and Australia, was established in 1997 to facilitate research into: -- the identification and characterisation of melanoma susceptibility genes, and -- the interactions of the effects of these genes with each other, and with relevant environmental exposures -chiefly solar ultraviolet (UV) radiation - in melanoma tumorigenesis. These goals will only be achieved by conducting sufficiently large studies of genetically diverse populations experiencing a range of environmental exposures: objectives beyond the capacity of any single group. The current proposal is specifically motivated by the Consortium's success, over a short period of time, in: --rapidly integrating information from the large number of multiple-case melanoma kindreds ascertained by its individual groups and initiating comparative penetrance and linkage studies, and -- successfully initiating new collaborative projects to map and identify melanoma predisposition genes over the past two years, which have identified significant new candidate loci for melanoma susceptibility genes. The general objectives of this proposal are: -- to maximise the epidemiological and genetic information derived from multiple-case melanoma kindreds ascertained by the Consortium in three continents